In a mobile communication system employing an LTE-Advanced scheme which is a next-generation communication scheme of an LTE scheme, a “relay node RN” having the same function as that of a radio base station DeNB can be connected between a mobile station UE and the radio base station DeNB.
As illustrated in FIG. 1, the LTE-Advanced mobile communication system is configured such that an E-RAB (E-UTRAN Radio Access Bearer, a bearer for a mobile station UE) is set between the mobile station UE and a gateway device S-GW (Serving-Gateway) as a bearer for a U plane, a Uu radio bearer (a first radio bearer) is set between the mobile station UE and a relay node RN, a Un radio bearer (a second radio bearer) is set between the relay node RN and the radio base station DeNB, and an S1 bearer is set between the radio base station DeNB and the gateway device S-GW.
However, there is a problem that at the current moment, in the LTE-Advanced mobile communication system, a method for mapping the E-RAB, the Uu radio bearer, the Un radio bearer, and the S1 bearer has not been defined.